I purchased a total loss 1997 vehicle. The model is 540I. the vehicle had front end damage so when I got the vehicle I tried to crank the engine for a couple of seconds and it cranked fine. I pulled the motor and then I took it to the body shop for body repair. When I got the vehicle back I put the motor back in and hooked up all the wiring but the engine will not turn over. I have no power going to the starter. I work in electronics so know a lot about wiring, I have done some trouble shooting but I am missing power for the starter from the ignition. I am stuck. Can anyone help me - what am I missing?? My key remote works fine for opening the doors, trunk, etc. but when I put it in the ignition it will not start.

I purchased a total loss 1997 vehicle. The model is 540I. the vehicle had front end damage so when I got the vehicle I tried to crank the engine for a couple of seconds and it cranked fine. I pulled the motor and then I took it to the body shop for body repair. When I got the vehicle back I put the motor back in and hooked up all the wiring but the engine will not turn over. I have no power going to the starter. I work in electronics so know a lot about wiring, I have done some trouble shooting but I am missing power for the starter from the ignition. I am stuck. Can anyone help me - what am I missing?? My key remote works fine for opening the doors, trunk, etc. but when I put it in the ignition it will not start.

Have you checked the connections at the starter with a meter? getting any voltage? when you turn the key to the ON position, do the lights on the dash light up? Follow the wires backwards from the starter to the power source and check all the connections for voltage.

My first instinct was to check the starter connection, so I went under the car and unplugged the two wires that go to the starter. Then, when I turn the ignition on to the start position there was no power coming to the plug at the starter. Then i took a long wire from the ignition to the starter plug direct - when I turn the ignition on the motor turns. This makes me realize i am missing power from the ignition to the starter. I then traced the ignition black wire with yellow line (the start wire) all the way under the hood to the passenger side where all the relays are. it goes to a plug and if I put a test light there and turn the ignition on the test light comes on. At the plug the black and yellow wire turns to a lighter weight of wire. From there it goes to a computer under the hood, where all the relays are. From there I can't tell where it goes - I am stuck. I am assuming that the vehicle imobilizer is shutting the starter power down, but am not sure if that is correct or not. If anybody has a diagram on how to bypass the immobilizer that might help. I would appreciate any help - or other suggestions.

Sometimes when battery voltage is low or battery disconnected for a long period of time the EWS (immobilizer) and DME (engine module) need to be re-synched. Only a dealership or a independent BMW shop with a good quality scan tool can do this. I would try this before going too far.